title: Comparison of extracted teeth and simulated resin blocks on apical canal transportation.
abstract: BACKGROUND
  We aimed to compare apical canal transportation of extracted teeth and two types of simulated resin blocks.
  
  
  METHODS
  Mesiobuccal root of extracted maxillary molars, high hardness simulated resin blocks (Knoop hardness=40) and low hardness simulated resin blocks (Knoop hardness=22) were prepared with K-files using step-back technique (n=15 canals in each group). Double exposure radiographic technique was used for extracted teeth. Simulated resin blocks were stabilized and scanned before and after preparation. Pre and post-preparation pictures were superimposed and apical transportation was measured. The data were analyzed statistically using ANOVA and Tukey HSD tests.
  
  
  RESULTS
  There was no significant difference in apical canal transportation between extracted teeth and high hardness resin blocks (P>0.05). Low hardness resin blocks showed more apical transportation than the other groups (P<0.05).
  
  
  CONCLUSIONS
  Under the conditions of this study, apical canal transportation for extracted teeth and high hardness simulated resin blocks were similar.
authors.affiliation: Department of Endodontics, Dental School, Islamic Azad University/ Iranian Center for Endodontic Research, Tehran, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Khalilak
authors.forename: Arjang
authors.initials: A
authors.lastname: Fallahdoost
authors.forename: Bahareh
authors.initials: B
authors.lastname: Dadresanfar
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Rezvani
keywords: Endodontics; Hardness; Instrumentation; Resin; Simulate; Tooth